The On-Line Encyclopedia of Integer Sequences (OEIS)

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A252531

Number of (n+2) X (7+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 2 3 6 or 7.
(history; published version)

#8 by Bruno Berselli at Tue Dec 04 11:04:15 EST 2018

STATUS

reviewed

approved

#7 by Michel Marcus at Tue Dec 04 10:52:57 EST 2018

STATUS

proposed

reviewed

#6 by Colin Barker at Tue Dec 04 10:40:46 EST 2018

STATUS

editing

proposed

#5 by Colin Barker at Tue Dec 04 10:40:24 EST 2018

NAME

Number of (n+2) X (7+2) 0..3 arrays with every 3X3 3 X 3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3X3 3 X 3 column and antidiagonal sum not equal to 0 2 3 6 or 7.

COMMENTS

Column 7 of A252532

FORMULA

Empirical: a(n) = 8*a(n-3) for n>5.

Empirical g.f.: 4*x*(300 + 367*x + 601*x^2 - 1610*x^3 - 72*x^4) / ((1 - 2*x)*(1 + 2*x + 4*x^2)). - Colin Barker, Dec 04 2018

EXAMPLE

Some solutions for n=4:

CROSSREFS

Column 7 of A252532.

STATUS

approved

editing

#4 by R. H. Hardin at Thu Dec 18 08:05:46 EST 2014

STATUS

editing

approved

#3 by R. H. Hardin at Thu Dec 18 08:05:42 EST 2014

LINKS

R. H. Hardin, <a href="/A252531/b252531.txt">Table of n, a(n) for n = 1..210</a>

#2 by R. H. Hardin at Thu Dec 18 08:05:28 EST 2014

NAME

allocated for R. H. Hardin

Number of (n+2)X(7+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 3 6 or 7

DATA

1200, 1468, 2404, 3160, 11456, 19232, 25280, 91648, 153856, 202240, 733184, 1230848, 1617920, 5865472, 9846784, 12943360, 46923776, 78774272, 103546880, 375390208, 630194176, 828375040, 3003121664, 5041553408, 6627000320

OFFSET

1,1

COMMENTS

Column 7 of A252532

FORMULA

Empirical: a(n) = 8*a(n-3) for n>5

EXAMPLE

Some solutions for n=4

..3..2..2..3..2..2..3..2..2....1..1..0..1..1..0..1..1..0

..3..1..3..3..1..3..3..1..3....0..1..1..0..1..1..0..1..1

..2..2..3..2..2..3..2..2..3....0..3..0..0..3..0..0..3..0

..3..2..2..3..2..2..3..2..2....1..1..0..1..1..0..1..1..0

..3..0..3..3..1..3..3..0..3....0..1..1..0..1..1..0..1..1

..2..2..3..2..2..3..2..2..3....3..3..0..0..2..0..0..2..0

KEYWORD

allocated

nonn

AUTHOR

R. H. Hardin, Dec 18 2014

STATUS

approved

editing

#1 by R. H. Hardin at Thu Dec 18 07:50:34 EST 2014

NAME

allocated for R. H. Hardin

KEYWORD

allocated

STATUS

approved